Telephone



(NoModeL) G. L. ANDERS.

Telephon.

No. 233,592. Patented Oct. 26,1880.

\X/iI 5.55125.

N-PETERS, PHOYO-HTNDGRAFMER, WASHINGTON. D. C.

UNITED mares ATENT Price.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 233,592, dated October 26, 1880.

Application filed June 21, 1880.

To all whom at may concern:

Be it known that I, GEORGE LEE ANDERS, ofBoston, county of Sufiolk, State of Massachusetts, have invented an Improvement in Telephones, of which the followingdescription, in connection with the accompanying drawings, is a specification.

My invention relates to telephones, and has for its object to increase the volume of sound transmitted wit-houtimpairin g the distinctness of articulation.

The invention is shown embodied in a magneto-telephone; and it consists chiefly in a novel construction of the diaphragm, and also in the combination of the said diaphragm with the magnetic poles, whereby a greater magnetic force and novel arrangement of induction-coils may be employed to enable stronger electric impulses to be used.

The diaphragm consists of two plates, such as commonly used for telephonic (liaphragms, the said plates being connected at theiredges with a slight space between them. One of the said plates is provided at its middle with an opening oppositethe sound-passage ot'the usual mouth-piece through which the sound-waves )ass. 1 The diaphragm is supported at the edge of the said central opening, so that the plate provided with the opening vibrates the most at its edge, and in such vibration the other plate which has the greatest vibration, and may be called the vibrating plate, being connected with the said edge, is vibrated bodily therewith, at the same time vibrating in the usual manner as if its edge were rigidly held.

A diaphragm constructed on this plan is more flexible and readily vibrated than one of the usual kind, and a larger portion of the mass of it is set in motion, the region of vibration not being confined to the central portion of the said diaphragm as when the edge is fixed in the usual manner, so that a magnetic field of larger extent can be utilized.

As herein shown, two horseshoe-magnets are used having four pole-pieces and inductioncoils thereon arranged around the center of the vibrating plate, so that nearly the whole area of the said plate is affected by the said magnets, a thing which would not be practicable it the plate were held motionless at its &

(No model.)

edges in the usual manner, as the vibrations at the part above the poles of the magnet would in that case be very slight.

Figure 1 is a longitudinal section of a magneto-telephone illustrating my invention, and Fig. 2 a plan of the poles of the magnet, the position of the diaphragm being indicated in dotted lines.

The magnets a bare shown as horseshoemagnets, each having two polepieces, 0, provided with the usual induction-coils d, thefour poles being symmetrically arranged opposite to the diaphragm c and mouth-piecef.

The diaphragm c is made of two plates, one of which, g, nearest to the poles of the magnets, may be such asused for a common diaphragm; but instead of being held at its edges, fixed to the frame-work, it is fastened to the edge of a second plate, h, similar to it, except that it has a central opening, 2', corresponding in shape and position to the sound-passage of the mouth-piecef.

The plate It is secured at the edges of the openingi to the end of the tubem, which formsa continuation of themouth-piecef. Thisforming the point of support upon which the diaphragm 0, taken as a whole, vibrates, the tubem and connected mouth-piece]? being supported on across-bar, n, which may be adjustably connected with the frame-work 0 in any desired manner to adjust the position of the plate g relative .to the poles 0.

The plates 9 h are placed a slight distance apart, an annular riu g or washer, a, being placed between them where joined together at their edges, a space thus being formed between the said plates corresponding to the usual sound chamber or space above the usual diaphragm.

The two plates g h being free at their edges, the plate 9, when set in vibration by the magnetic impulse or by sound-waves entering the mouth-piece f, is vibrated bodily, the edges of the two disks vibratiu g 011 account of the flexibility of the plate h. In this manner themagnetic force of the four poles may be utilized; for, although situated at a distance from the center of the plate g, where the vibrations are l of greatest amplitude, the vibration opposite the poles is, owing to the freedom of the edges of the plates 9 h, sufficient to produce the desired effect, and nearly the whole mass of the plate g acts as a movable armature for the magnets, instead of a small area near the center thereof, as would be the case it the edges were fixed as usual.

The plate g, besides its bodily movement, also vibrates within itself, owing to its own flexibility, and it will be seen that the flexibility of both plates is involved in the vibration of the central portion of the plate g, the diaphragm, as a whole, thus having a much easier and more delicate movement than a diaphragm of ordinary construction.

A diaphragm of this sort is useful in other instruments besides magneto-telephones, and it will be seen that the plate h need not be of magnetic material. The flexible plate or diaphragm h, fixed near its center and free to vibrate at its edges, may be used in connection with a rigid plate to form an armature or vibrator to take the place of the flexible plate When a number of pole-pieces and inductioncoils thereon are employed with a single diaphragm, as herein shown, the said coils may be connected in multiple are or in series, as demanded by the exigencies of the case.

I claim- 1. An instrument comprising a plate or diaphragm supported at a suitable distance from the edges, leaving these free to vibrate, a second plate or diaphragm, joined to the firstnamed at the edges, and devices for transmitting or reproducing sound-vibrations connected with said second plate or diaphragm, sub stantially as described.

2. The combination with a magnet, of two plates or diaphragms connected at the edges, one supported at or near the center and the other forming or carrying an armature to said magnet, substantially as described.

3. In a telephone, the combination, with the mouth-piece and sound-passage, of a vibrator or diaphragm consisting of two plates fastened together at their edges, the one adjacent to the mouth-piece having a central opening'corresponding to the sound-passage and being at the edges of said opening attached to a fixed support, the other portions of the connected plates being free to vibrate, substantially as and for the purpose described.

4. In a magneto-telephone, a plate or diaphragm, fixed near its center and free to vibrate at its edges, and an armature attached to the said edges and adapted to be vibrated bodily, combined with a series of magnetic poles and induction-coils thereon arranged around the center of the said armature, as and for the purpose described.

5. In a telephone, the sou lid-passage and two plates or diaphragms, and an annular ring or washer between them at their connected edges, to form a space between the said plates, one of the said plates being provided with a central opening and connected at the edges thereof with a fixed support at the end of the soundpassage, to permit the sound-waves to pass through the said passage, and opening to and from the other one of the said plates, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEORGE LEE ANDERS.

Witnesses:

J os. P. LIVERMORE, N. E. O. WHITNEY. 

